Sharp R-305EW Service Manual

Table of Contents

Quick Links

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO

AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ................... INSIDE FRONT COVER

BEFORE SERVICING ...................................................................................................... INSIDE FRONT COVER

WARNING TO SERVICE PERSONNEL ................................................................................................................ 1

MICROWAVE MEASUREMENT PROCEDURE ................................................................................................... 2

FOREWORD AND WARNING ............................................................................................................................... 3

PRODUCT SPECIFICATIONS .............................................................................................................................. 4

GENERAL INFORMATION ................................................................................................................................... 4

OPERATION .......................................................................................................................................................... 6

TROUBLESHOOTING GUIDE .............................................................................................................................. 9

TEST PROCEDURE ............................................................................................................................................ 10

TOUCH CONTROL PANEL ................................................................................................................................. 18

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 22

PICTORIAL DIAGRAM ........................................................................................................................................ 28

POWER UNIT CIRCUIT ...................................................................................................................................... 29

CPU UNIT CIRCUIT ............................................................................................................................................ 30

PRINTED WIRING BOARD ................................................................................................................................. 31

PARTS LIST ........................................................................................................................................................ 32

PACKING AND ACCESSORIES ......................................................................................................................... 36

SHARP CORPORATION

SERVICE MANUAL

NO.

LBS.

CUPS.

COOK

DEFOST

OZ.

MINUTE PLUS

INSTANT ACTION

TO ADJUST QUANTITY TOUCH

PAD AGAIN

POPCORN

DINNER PLATE

CASSEROLE

BAKED POTATOES

FRESH VEGETABLE

GROUND MEAT

FROZEN ENTREES

BEVERAGE

ROLLS / MUFFINS

1 GROUND MEAT

COMPU

2 STEAKS/CHOPS

DEFROST

3 CHICKEN PIECES

POWE R

TIMER

LEVEL

CLOCK

STOP

CLEAR

STAR T

In the interest of user-safety the oven should be restored to its original

condition and only parts identical to those specified should be used.

WARNING TO SERVICE PERSONNEL: Microwave ovens con-

tain circuitry capable of producing very high voltage and

current, contact with following parts may result in a severe,

possibly fatal, electrical shock. (High Voltage Capacitor, High

Voltage Power Transformer, Magnetron, High Voltage Recti-

fier Assembly, High Voltage Harness etc..)

MICROWAVE OVEN

R-305EW

MODEL

This document has been published to be used for after

sales service only.

The contents are subject to change without notice.

R-305EW

S2104R305EPW/

Page

Table of Contents

Summary of Contents for Sharp R-305EW

Page 1: Table Of Contents
R-305EW SERVICE MANUAL S2104R305EPW/ MICROWAVE OVEN LBS. CUPS. COOK DEFOST R-305EW MINUTE PLUS INSTANT ACTION TO ADJUST QUANTITY TOUCH PAD AGAIN MODEL POPCORN DINNER PLATE CASSEROLE BAKED POTATOES FRESH VEGETABLE GROUND MEAT FROZEN ENTREES BEVERAGE ROLLS / MUFFINS 1 GROUND MEAT...
Page 2: Precautions To Be Observed Before And During Servicing To Avoid Possible Exposure To Excessive Microwave Energy
Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS CORPORATION immediately @1-800-237-4277. If the unit operates with the door open, service person should 1) tell the user not to operate the oven and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's Center for Devices and Radiological Health immediately.
Page 3: Warning To Service Personnel
R-305EW WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of pro- ducing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock. (Example) High Voltage Capacitor, High Voltage Power Trans- former, Magnetron, High Voltage Rectifier Assem- bly, High Voltage Harness etc..
Page 4: Microwave Measurement Procedure
R-305EW MICROWAVE MEASUREMENT PROCEDURE A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm at any point 5cm or more from the external surface of the oven, measured prior to acquisition...
Page 5: Foreword And Warning
MICROWAVE OVEN R-305EW GENERAL INFORMATION FOREWORD This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVEN, R-305EW. OPERATION It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory customer service.
Page 6: Product Specifications
R-305EW SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts / 13 Amperes 60 Hertz Single phase, 3 wire grounded Power Output 1100 watts (IEC TEST PROCEDURE) Operating frequency of 2450MHz Case Dimensions Width 20-1/2" Height 11-7/8" Depth 17-1/8" Cooking Cavity Dimensions Width 14-3/4"...
Page 7: Oven Diagram
R-305EW contact a qualified electrician and have it replaced with a properly Grounded 3-Pronged Plug grounded three-pronged wall receptacle or have a grounding adapter Receptacle Box properly grounded and polarized. If the extension cord must be used, it should be a 3-wire, 15 amp. or higher rated cord. Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally.
Page 8: Operation
R-305EW OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during relay and is mechanically associated with the door so oven operation. that it will function in the following sequence. (1) When the door opens from the closed position, the...
Page 9: Oven Schematic-Cooking Condition
R-305EW SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED NOTE: Indicates components with potential above 250 V. 2. CLOCK APPEARS ON DISPLAY THERMAL MONITOR THERMAL CUT-OUT (OVEN) FUSE 20A CUT-OUT (MG.) N.O. POWER N.O. TRANSFORMER (RY-2) (RY-1) PRIMARY INTERLOCK RELAY CONTROL UNIT COM.
Page 10 R-305EW DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH, The door is opened by pulling the door. Refer to the Figure PRIMARY INTERLOCK RELAY (RY2), RELAY D-1. (RY1), SECONDARY INTERLOCK SWITCH...
Page 11: Troubleshooting Guide
R-305EW TROUBLESHOOTING GUIDE Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected. When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed.
Page 12: Test Procedure
R-305EW CK = Check / RE = Replace RE RE A B C D E F F G H RE RE CK I CK CK CK J K L M TEST PROCEDURE PROBLEM CONDITION Home fuse or circuit breaker blows...
Page 13 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER 4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm. 5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground.
Page 14 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER HIGH VOLTAGE RECTIFIER TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectifier terminals and observe meter reading.
Page 15 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE THERMAL CUT-OUT. SECONDARY INTERLOCK SWITCH TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open.
Page 16 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER 5. Reconnect all leads removed from components during testing. 6. Reinstall the outer case (cabinet). 7. Reconnect the power supply cord after the outer case is installed. 8. Run the oven and check all functions.
Page 17 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER c) When touching the pads, sometimes a pad produces no signal. If the Key unit is defective. 1) Disconnect the power supply cord, and then remove outer case. 2) Open the door and block it open.
Page 18 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER 8. Run the oven and check all functions. MINUTE ROLLS / PLUS MUFFINS FRESH VEGETABLES FROZEN POWER TIMER COMPU DINNER CASSEROLE POPCORN START ENTREES LEVEL PLATE CLOCK DEFROST STOP BAKED GROUND BEVERAGE POTATOES...
Page 19 R-305EW TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER FOIL PATTERN ON THE PRINTED WIRING BOARD TEST To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on the PWB, this foil pattern acts as a fuse.
Page 20: Touch Control Panel
R-305EW TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units. 3) Power Source Circuit This circuit generates voltages necessary in the control (1) Key Unit unit from the AC line voltage.
Page 21 R-305EW Pin No. Signal Description Back light circuit (Light emitting diodes) driving signal. 12-13 P56-P55 Terminal not used. CNTR0 Signal to sound buzzer (2.0 kHz). 0.1 sec. H : GND A: key touch sound. L : -5V B: Completion sound.
Page 22 R-305EW Pin No. Signal Description Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P41, P43, P44 and P45 terminal while one of G8 line keys on key matrix is touched. Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P41, P43, P44 and P45 terminal while one of G7 line keys on key matrix is touched.
Page 23 R-305EW TOUCH CONTROL PANEL SERVICING A. On some models, the power supply cord between the 1. Precautions for Handling Electronic Components touch control panel and the oven itself is so short that the This unit uses CMOS LSI in the integral part of the two can’t be separated.
Page 24: Component Replacement And Adjustment Procedure
WARNING FOR WIRING To prevent an electric shock, take the following pre- and Oven cavity. cautions. 3) Sharp edge: 1. Before wiring, Bottom plate, Oven cavity, Waveguide flange, 1) Disconnect the power supply cord. Chassis support and other metallic plate.
Page 25 R-305EW CAUTION: 1. DISCONNECT OVEN FROM POWER SUP NOTE: When replacing the outer case, the 2 special PLY BEFORE REMOVING OUTER CASE. Torx screws must be reinstalled in the same 2. DISCHARGE THE HIGH VOLTAGE CA- locations. PACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.
Page 26: Control Panel Assembly Removal
R-305EW 9. Now, the magnetron is free. 4. Reconnect the wire leads to the magnetron and thermal Reinstallation cut-out (MG). Refer to "PICTORIAL DIAGRAM" on page 1. Re-install the magnetron to waveguide flange with the four (4) screws. 5. Re-install outer case and check that the oven is operating 2.
Page 27 4. Where the corners have been snipped off bend corner 7. Now the turntable motor is free. areas flat. No sharp edges must be evident after removal 8. After replacement use the one (1) screw to fit the of the turntable motor cover.
Page 28 R-305EW DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL Reinstallation 1. Disconnect the power supply cord and remove outer case. 1. Re-install each switch in its place. The secondary 2. Open the door and block it open. interlock/monitor switches are in the lower position and 3.
Page 29 R-305EW 11.Now, door panel with sealer film is free. 12.Tear sealer film from door panel. 13.Now, door panel is free. Upper Oven 14.Slide latch head upward and remove it from door frame Upper Hinge Oven Hinge with releasing latch spring from door frame and latch head.
Page 30: Pictorial Diagram
R-305EW RECTIFIER H.V.
Page 31: Power Unit Circuit
R-305EW CN-C CN-A 9PIN LEAD WIRE HARNESS S1NB10 – OVEN LAMP TURNTABLE BUZZER MOTOR FAN MOTOR OVEN LAMP TURNTABLE MOTOR FAN MOTOR MICRO MICRO SH-A DOOR DOOR SH-B SENSING SENSING SWITCH SWITCH...
Page 32: Cpu Unit Circuit
R-305EW COM1 COM2 COM3 SEG22 SEG21 SEG20 SEG19 SEG18 SEG17 SEG16 SEG15 SEG14 SEG13 SEG12 SEG11 SEG10 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG0 VREF XOUT AVSS COM3 COM2 COM1 RESET COM0 4.7k 4.7k 4.7k /25v 0.01 UDZ4.3B 270k...
Page 33: Printed Wiring Board
R-305EW SH - B CN - C (D2) (D3) CN - A Figure S-4. Printed Wiring Board of Power Unit...
Page 34: Parts List
R-305EW PARTS LIST Note: The parts marked “ ” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO. PART NO. DESCRIPTION Q'TY CODE ELECTRIC PARTS 1- 1 QSW-MA147WRZZ 2nd interlock switch / door sensing switch...
Page 35 To have your order filled promptly and correctly, please furnish the following information. 1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION Order Parts from the authorized SHARP parts Distributor for your area. Defective parts requiring return should be returned as indicated in the Service Policy.
Page 36: Oven And Cabinet Parts
R-305EW OVEN AND CABINET PARTS 4-18 7-10 1-10 1-11 4-17 4-20 4-13 4-11 4-19 4-10 4-16 4-23 4-18 4-12 4-16 4-15 1-13 4-14 1-12 1-14 4-22 4-21...
Page 37 R-305EW CONTROL PANEL PARTS DOOR PARTS 3-3-1 5-11 5-10 5-10 MISCELLANEOUS (CAPACITOR) Actual wire harness may be different from illustration.
Page 38: Packing And Accessories
R-305EW TOP PAD ASSEMBLY FPADBA416WRKZ PACKING AND ACCESSORIES DOOR PROTECTION SHEET SPADPA204WRE0 PLASTIC BAG SSAKHA034WRE0 6- 8 INSTRUCTION BOOK & PRINTING MATTER 6- 2 TURNTABLE TRAY BOTTOM PAD ASSEMBLY FPADBA417WRKZ 6- 1 TURNTABLE SUPPORT TRAY PACK INTO THE SPADFA451WRE0 OVEN CAVITY Not replaceable items.
Page 39 R-305EW...
Page 40 No part of this publication may be repro- duced, stored in retrieval systems, or trans- mitted in any form or by any means, elec- tronic, mechanical, photocopying, record- ing, or otherwise, without prior written per- mission of the publisher. 2001 SHARP CORP. (2S2.530E) Printed in U.S.A...

Sharp R-305EW Service Manual

Quick Links

TABLE OF CONTENTS

Related Manuals for Sharp R-305EW

Summary of Contents for Sharp R-305EW

Table of Contents